Complex regional pain syndrome (CRPS) is a condition of intense burning pain, stiffness,
swelling, and discoloration that most often affects the hand. Arms, legs, and feet
can also be affected by CRPS.

This condition was previously known as reflex sympathetic dystrophy, Sudeck's atrophy,
shoulder-hand syndrome, or causalgia.

Description

There are two types of CRPS:

Type 1 occurs after an illness or injury that did not directly damage a nerve in the
affected area

Type 2 follows a distinct nerve injury

Although the triggers vary, both types of CRPS have the same symptoms and go through
the same three stages of disease.

Stage I: Acute

Stage I may last up to 3 months. Burning pain and increased sensitivity to touch are
the most common early symptom of CRPS. This pain is different — more constant and
longer lasting — than would be expected with a given injury. Swelling and joint stiffness
usually follow, along with increased warmth and redness in the affected limb. There
may be faster-than-normal nail and hair growth and excessive sweating.

Acute stage CRPS, 2 months after injury

Stage II: Dystrophic

Stage II can last 3 to 12 months. Swelling is more constant and skin wrinkles disappear.
Skin temperature becomes cooler. Fingernails become brittle. Pain is more widespread,
stiffness increases, and the affected area becomes more sensitive to touch.

Stage III: Atrophic

Stage III occurs after 1 year. The skin of the affected area becomes pale, dry, tightly
stretched, and shiny. The area is stiff and there is less hope of getting motion back.
Pain may decrease and the condition may spread to other areas of the body.

Although the two types of CRPS can be tied to injury or illness, the exact cause of
CRPS is unknown. One theory is that a "short circuit" in the nervous system is responsible.
This "short circuit" causes overactivity of the sympathetic (unconscious) nervous
system which affects blood flow and sweat glands in the affected area.

Symptoms most commonly occur after injury or surgery. Other causes include pressure
on a nerve, infection, cancer, neck problems, stroke, or heart attack.

Injection therapy. Injecting an anesthetic (numbing medicine) near the affected sympathetic nerves can
reduce symptoms. This is usually recommended early in the course of CRPS in order
to avoid progression to the later stages.

Biofeedback. Increased body awareness and relaxation techniques may help with pain relief.

Therapy. Active exercise that emphasizes normal use of the affected limb is essential to permanent
relief of this condition. Physical and/or occupational therapy are important in helping
patients regain normal use patterns. Medications and other treatment options can reduce
pain, allowing the patient to engage in active exercise.

Surgical Treatment

If nonsurgical treatment fails, there are surgical procedures that may help reduce
symptoms.

AAOS does not endorse any treatments, procedures, products, or physicians referenced
herein. This information is provided as an educational service and is not intended
to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance
should consult his or her orthopaedic surgeon, or locate one in your area through
the AAOS "Find an Orthopaedist" program on this website.